• 제목/요약/키워드: Chiral capillary electrophoresis

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Enantioselective electrophoretic behavior of lipoic acid in single and dual cyclodextrin systems

  • Le, Thi-Anh-Tuyet;Nguyen, Bao-Tan;Phan, Thanh Dung;Kang, Jong-Seong;Kim, Kyeong Ho
    • 분석과학
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    • 제34권4호
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    • pp.143-152
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    • 2021
  • Capillary electrophoresis (CE) is an effective technique to study chiral recognition because it offers flexibility in adjusting vital factors. Currently, various available cyclodextrins (CDs) can be employed for the chiral separation of numerous analytes. Herein, we investigate the enantioseparation behavior of lipoic acid enantiomers in various types of single and dual CD systems through CE. Additionally, several impacted CE parameters were optimized through the systematic investigation based on the design of experiment (DoE) concept for a single system comprising a heptakis (2,3,6-tri-O-methyl)-β-CD and a dual system containing the combination of the single CD with a sulfated-β-CD. Consequently, absolute enantioresolution was obtained within 15 min on a common standard bare fused-silica capillary (64.5/56 cm in total/effective length, 50/365 ㎛ inner/outer diameter), maintained at 15 ℃ and at an applied voltage of 24 kV. The optimal background electrolyte consisted of 6 mM heptakis (2,3,6-tri-O-methyl)-β-CD dissolved in the solution of 58 mM borate buffer at pH 10. Furthermore, the results of apparent binding constant experiments indicated that the S-enantiomer-heptakis (2,3,6-tri-O-methyl)-β-CD complex exhibited a stronger affinity than its R-enantiomer counterpart. The obtained electrophoretic mobility values could be utilized to interpret the resolution achieved at various CD concentrations and the mobility behavior of the complexes elucidated the migration order of the enantiomers in an electropherogram.

Chiral Separation of Aromatic Amino Acids by Capillary Electrophoresis using (+)-18-crown-6 tetracarboxylic acid and (-)-18-crown-6 tetracarboxylic acid as Chiral Selectors

  • Choi, Young-Me;La, Sook-Ie;Lee, Won-Jae;Kim, Kyoung-Rae
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.278.1-278.1
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    • 2003
  • Recently, particular attention has been paid to the chiral separation of amino acid enantiomers because of their different biological activities. Hence, the high optical purity of aromatic amino acids is critical because of their important functions in the central nervous system. For the accurate chiral discrimination. we attempted to exploit the crosschecking each enantiomeric migraion orders of aromatic amino acids measured using (+)-18C6H4TA and (-)-18C6H4TA as the chiral selectors under pH 2.0, tris/citric acid buffer.

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Enantioselective Pharmacokinetics of Carvedilol in Human Volunteers

  • Phuong, Nuyen-Thi;Lee, Beam-Jin;Choi, Jung-Kap;Kang, Jong-Seong;Kwon, Kwang-il
    • Archives of Pharmacal Research
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    • 제27권9호
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    • pp.973-977
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    • 2004
  • Carvedilol is administered as a racemic mixture of the R(+)- and S(-)-enantiomers, although they exhibit different pharmacological effects. To investigate the stereoselective pharmacoki-netics, the enantiomeric separation of carvedilol in human plasma was undertaken using capil-lary electrophoresis (CE). Resolution of the enantiomers was achieved using 2-hydoxypropyl-$\beta$-cyclodextrin as the chiral selector. Phosphate buffer (50 mM, pH 4.0) containing 10 mM of 2-hydoxypropropyl-$\beta$-cyclodextrin was used as electrolytic buffer. Achiral separation was carried out with the same electrolytic buffer without chiral selector. Following a single oral administra-tion of 25-mg carvedilol to 11 healthy, male volunteers, stereoselective pharmacokinetic analy-sis was undertaken. The maximum plasma concentrations ( $C_{max}$) were 48.9 and 21.6 ng/mL for (R)-carvedilol and (S)-carvedilol, respectively, determined by the chiral method. The profiles of the plasma concentration of (RS)-carvedilol showed $C_{max}$ of 71.5, 72.2, and 73.5 ng/mL, as determined by the CE, HPLC/FD methods and calculations from the data of the chiral method, respectively.y.y.

Determination of Stability Constants of the Inclusion Complexes of ${\beta}$-Blockers in Heptakis (2,3-Dimethyl-6-Sulfato)- ${\beta}$-Cyclodextrin

  • Phuong, Nuyen Thi;Lee, Kyung-Ah;Kim, Kyung-Ho;Choi, Jung-Kap;Kim, Jong-Moon;Kang , Jong-Seong
    • Archives of Pharmacal Research
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    • 제27권12호
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    • pp.1290-1294
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    • 2004
  • The ${\beta}$-blockers possess at least one chiral center and the S(-)-enantiomer shows higher affinity for binding to the ${\beta}$-adrenergic receptors than antipode. The stability constants of acebutolol, celiprolol, propranolol and terbutaline in the inclusion complexes with single-isomer heptakis (2,3-dimethyl-6-sulfato)- ${\beta}$-cyclodextrin (HDMS-${\beta}$-CD) were determined by capillary electrophoresis. The approximation and linear double reciprocal methods were adapted with comparable results. Among the ${\beta}$-blockers studied, propranolol had the lowest stability constant but the highest enantioselectivity, indicating that the magnitudes of the stability constants carried little information about enantioseparation. The magnitudes of enantioselectivities between the enantiomer pair were in the order of propranolol > celiprolol > terbutaline > acebutolol.